Numerical analysis of the effect of middle-ear effusion on the sound transmission and energy absorbance of the human ear

This study aims to investigate the impact of middle ear effusion (MEE) on sound transmission in the human ear and its potential diagnostic significance. Firstly, the material properties of specific structures were adjusted based on the existing human ear finite element (FE) model, and the accuracy of the model was validated using experimental data. Secondly, six FE models were developed to simulate varying degrees of MEE by systematically altering the material properties of the middle ear cavity (MEC) at different anatomical locations. Finally, the effects of these six FE models, representing varying degrees of MEE, on sound transmission characteristics and energy absorption (EA) rate in the human ear were systematically analyzed. When the degree of MEE is less than 50% of the MEC volume, its impact on the sound transmission characteristics of the human ear remains minimal, resulting in an estimated hearing loss of approximately 3 dB, with EA rate remaining close to normal levels. Once the effusion exceeds 50% of the MEC volume, a significant deterioration in acoustic transmission is observed, accompanied by a flattening of the EA curve and a drop in EA rates to below 20%. When the effusion completely fills the MEC, the maximum hearing loss reaches 46.47 dB, and the EA rate approaches zero across the entire frequency range. These findings provide theoretical insights into the biomechanical effects of MEE on human auditory transmission and offer a reference for clinical diagnosis and evaluation.